The most industrial slag, such as mine scoria, steel slag, coat ash, coat residue, etc. once were buried after compression or sterilization, or simply used as additive. Later on, it has been found that almost aft the industrial waste slag can find its application in architecture. Particularly, through powder grinding process, the industrial waste slag can be used as additive in building mixture material, concrete and the product made of them. The prior art powder grinding process and apparatus for industrial waste slag is as follows: removing the iron from the industrial waste slag by means of iron-removing device; cracking the waste slag by means of a cracking device; transferring the broken waste slag into a hopper by means of a lifting device; transferring the waste slag into the rotary type or vertical type of drying device after metering; drying the waste slag through a hot air furnace, therefore the water contained in the waste slag evaporates into steam, which, together with the smog, flow into a deduster in order to remove the dust; after purifying, the gases are discharged into the atmosphere through a gas guiding device; the collected dust and the dried waste slag are conveyed to a lifting device by a conveyor, and lifted into a storing tank; after re-metering, transferring the waste slag to a ball grinder and powder grinding the waste slag, after grinding, then a fine finished product is obtained; the waste gases produced during powder grinding procedure are discharged into the atmosphere through a air guiding device after being dedusted by a deduster, the collected dust together with the finished product are lifted into the storing tank by a lifting device.
Since the prior process is a open process, it has tong flowing process, it is inconvenient to control and adjust the process, the yield is low, the fineness after powder grinding can not be guaranteed, the apparatus occupy too much space, a separate drying system is needed, the cost of investment is high, the automatic level is low, the energy consumption is high, the working efficiency is low, it only adapts to one single kind of product, the economic benefit is insignificant. Therefore, there are only a few enterprises that manufacture the industrial waste slag grinding.